Plano-concave lens, N-BK7, Ø 12.7 mm, f = -50 mm, mounted, ARHS-YAG

Plano-concave singlet in N-BK7, Ø 12.7 mm, focal length -50 mm, in a mount. ARHS-YAG V-coat coating. Negative focal length: diverges the beam, for beam expanders and to shorten system length.